It will hang or fall largely on the restrictions on the RN, more specifically the introduction of the French fleet. Cornwallis was engaged in a campaign fairly similar to later Imperial campaigns throughout the world, and maintained reasonable c & c while expecting better resources as time allowed upon which the Patriots could not similarly rely. The lynchpin of this or any Imperial campaign of course rested on naval control, and as soon as that was impeded the entire campaign collapsed. I'd argue that with Howe but with France still impeding they lose, whereas without Howe but without France they win.